The present invention relates to the automatic analyzer to analyze components of a sample using a reagent or the like, and particularly to automatic analyzer ensuring improved efficiency of agitation between said reagent or the like and sample.
Techniques used in the agitator of the prior automatic analyzer include the method of inserting a spatula-shaped agitating rod directly in the reaction vessel and giving it rotation or reciprocating motion, thereby conducting agitation between the sample and reagent or the like, and the method disclosed in the Japanese Official Patent Gazette 038011/1991 where agitation is accomplished by tilting and rotating the reaction vessel.
Other known methods include the method disclosed in the Japanese Official Patent Gazette 123136/1998 where the reagent itself is synthesized with magnetic magnetic particulates and agitation is performed by external magnetism, and the method disclosed in the Japanese Official Patent Gazette 189889/1996 where a barrier is provided in the reaction vessel and a clearance is provided on the bottom of said reaction vessel to allow free passage of liquid so that agitation can be performed by pneumatic pressure.
However, in the method of inserting a spatula-shaped agitation rod into the reaction vessel, a phenomenon called carry-over occurs where reagent or sample deposited on the agitation rod affects the result of the following analyses, if a sufficient washing of the agitation rod cannot be ensured.
To solve this problem, vibration is applied to the agitation to assist removal of the sample or reagent deposited on the agitation rod, as disclosed in Japanese Official Patent Gazette 58941/1994.
The method of applying vibration to the agitation rod requires a sufficient opening area of the reaction vessel to insert the agitation rod and to provide agitation or reciprocating motion. This requires a reaction vessel of a large capacity, and the amount of the sample stored in this big reaction vessel must be increased.
If the amounts of sample and reagent are reduced in order to reduce the physical load of the sample provider and to reduce the running cost of the equipment, light must be measured close to the bottom of the reaction vessel when optical measurement is conducted. To maintain accuracy of measurement close to the bottom of the reaction vessel, the reaction vessel must be provided with special processing.
For this reason, the method of giving vibration to agitation rod results in increased costs. This is not preferred from the view point of cost reduction.
In the method of mixing and agitation of the sample and reagent or the like by tilting and rotating the reaction vessel, solution is likely to scatter a splash of solution may be mixed with other objects to be analyzed.
The method of using reagent including magnetic particulates requires reagent to be developed, and this raises cost problems.
The method of installing a barrier to the reaction vessel to provide agitation through pneumatic pressure requires the reaction vessel to be subjected to special processing, and this also involves cost problems.
A method is disclosed and claimed in Japanese Official Patent Gazette 146007/1996. The technique in this Gazette uses ultrasonic wave to agitate the sample and reagent or the like. It allows the sample and reagent or the like to be agitated without being touched by other substances. It does not contaminate other samples and reagents or the like, and does not require use of an agitation rod. This makes it possible to reduce the size of the reaction vessel and to decrease the amount of sample and reagent.
As described above, use of ultrasonic wave for agitation of the sample and reagent or the like in the agitator of the automatic analyzer allows agitation to be performed without touching the sample and reagent or the like, and does not contaminate other samples and reagents or the like. In addition, since no agitation rod is used, it is possible to reduce the size of the reaction vessel and to decrease the amounts of the sample and reagent.
However, if excessive ultrasonic wave intensity is used for agitation, the portion of the reaction vessel wall allowing sound wave to pass by will be heated when ultrasonic wave is applied with few solution specimens or no specimens at all in the reaction vessel. This may cause the surf ace of the reaction vessel to be distorted, depending on the materials.
This may dampen the amount of light which is applied for absorbance measurement and which passes through the reaction vessel, and may lead to failure in accurate absorbance measurement.
There are a great varieties reagents used for colorimetric analysis. When ultrasonic wave of the same intensity is applied, fluidity is more likely to occur, and mixing capacity is higher if the reagent having greater wettability with the reaction vessel is used.
This requires ultrasonic wave intensity to be set for each reagent. It is necessary to monitor the state of agitation, namely, absorbance measurements in real time, and to set up ultrasonic wave intensity. The reagent vessel must be moved to the light measuring position to conduct absorbance measurement every time. These steps are quite complicated, and much time must be used for absorbance measurement.
The object of the present invention is to provide an automatic analyzer that ensures accurate absorbance measurement even if ultrasonic wave intensity becomes excessive for agitation of sample and reagent or the like.
Another object of the present invention is to provide an automatic analyzer which ensures accurate absorbance measurement even when ultrasonic wave intensity for agitation of the sample and reagent or the like becomes excessive, and which allows optimization of the ultrasonic wave intensity in a short time.
To achieve said object, the present invention has the following composition:
(1) An automatic analyzer comprising;
a reaction vessel where solution specimen is mixed with reagent to react with it,
a light source to apply light to said reaction solution and
an analysis unit to analyze light passing through said reaction solution;
wherein said automatic analyzer further comprises an agitator to apply ultrasonic wave to said reaction solution and to agitate said reaction solution, and
the direction of the ultrasonic wave emitted from said agitator and the direction of the light applied to said reaction solution are deviated from each other by at least the size of the spot irradiated by ultrasonic wave.
When the ultrasonic wave applied to the surface exposed to ultrasonic wave is excessive, the spot surface of the reaction vessel exposed to the ultrasonic wave may be deformed by heat generation or the like. If the surface of the deformed reaction vessel overlaps the surface exposed to the light passing through the reaction solution (absorbance measuring surface), then correct measurement may not be obtained.
As described above, if the surface exposed the light passing through the reaction solution does not overlap the spot exposed to ultrasonic wave, no error occurs to the result of the measurement. This makes it possible to produce an automatic analyzer which ensures accurate measurement of absorbance despite excessive intensity of ultrasonic wave due to agitation between sample and reagent.
The direction of deviation can be either vertical or lateral.
(2) An automatic analyzer comprising;
a reaction vessel where solution specimen is mixed with reagent to react with it,
a light source to apply light to said reaction solution and
an analysis unit to analyze light passing through said reaction solution;
wherein said automatic analyzer further comprises an agitator to apply ultrasonic wave to said reaction solution and to agitate said reaction solution, and
ultrasonic wave coming from said agitator and light applied to said reaction solution can be emitted simultaneously.
This composition allows the state of agitation to be monitored further on the real-time basis by means of the measurement of light, so the optimization of agitation conditions is facilitated.
(3) In (1) described above, said reaction vessel may have a form of prism and the surface exposed to ultrasonic wave emitted from said agitator may be different from the surface exposed to light applied to said reaction solution.
The reaction vessel can be shaped like either a cylinder or prism. If it has a form of prism, the direction of the light applied to reaction solution can be easily deviated from the direction of the ultrasonic wave emitted by at least the size of the spot irradiated by ultrasonic wave by changing the prism-formed surface exposed to ultrasonic wave and the prism-formed surface exposed to light. For example, when a prism-formed reaction vessel is used, the angle of irradiation can be deviated 90 deg.
(4) In (2) described above, irradiation conditions of ultrasonic wave coming from said agitator can be controlled, based on the result of analyzing the light passing through said reaction solution.
(5) In (4) described above, the reagent for agitation and regulation can be used to analyze the light passing through reaction solution and to determine the optimum irradiation conditions of ultrasonic wave.
(6) In (5) described above, said optimum irradiation conditions of ultrasonic wave can be stored in memory and ultrasonic wave irradiation conditions can be determined in the analysis using the reagent other than that for agitation and regulation, based on said irradiation conditions.